Check the small lines going to the vacuum tree and see if any are blocked.

People have had luck changing the PCV system. It should delay the RMS replacement and also save the cam seal. It is a 5 hour job to replace the oil separator box, leave the injectors in the manifold if you can.

I used a screwdriver to clean out the crud in the hole in the block where the plastic box fits into it. Try not to scratch the block.

The manifold has a support that bolts to it next to the bolt for the dipstick. Make sure the bottom support bolt is loose before trying to put the mani back on and then tighten the top bolt before you tighten the bottom bolt.

Do NOT overtighten the injector rail 2 screws if you take them off. They torque at 1 lb/ft, just snug.

Klaus
--
Volvoless. Sold the R. There is now a void...